A wind turbine generator is an apparatus in which a rotor head including a wind turbine blade is rotated by wind power, and a generator driven by increasing the speed of the rotation with a gear box or the like generates electricity.
The above-described rotor head is mounted to an end of a nacelle that is provided on a wind turbine tower (hereinafter referred to as “tower”) and can yaw, and supported rotatably around a substantially horizontal, lateral rotation axis.
In a conventional wind turbine generator, devices in a rotor head are hoisted, lowered and replaced in the following procedure.
First, an operator enters inside the rotor head, and removes a replacement device mainly by human power. Then, the replacement device is moved into a nacelle by human power, and moved down to the ground using a winch provided in the nacelle.
When newly mounted, a replacement device is lifted from the ground into the nacelle using the winch, and then moved from inside the nacelle to the rotor head by human power in reverse order of the removal operation.
For a conventional wind turbine generator, a method for hoisting and lowering a wind turbine facility is known using a reciprocating winch lifted by a permanent winch in a nacelle to reduce costs required for a hoisting and lowering operation of a large facility in the nacelle (for example, see Patent Literature 1).
Patent Literature 2 listed below discloses a technique on a method for transporting a wind turbine generator.